Military, police and civilians fell silent as the vehicles drove from the helicopter debris to the A149 Coast Road as they began their journey to the Norfolk and Norwich University Hospital.

The sombre scene was also observed by journalists and Brendan Joyce, chief executive of the Norfolk Wildlife Trust, which owns the Cley Marshes.

Mr Joyce said: “We all fell silent from the moment the vehicles started moving from the beach area to the Cley road. It brought home the sadness of it all.”

Chief supt Bob Scully, from Norfolk police, said yesterday it was a priority to remove the bodies in a “sensitive and dignified” way.

The Cley Marshes Visitors Centre continues to be used as a base for the investigation teams – including USAF and the RAF.

Large vehicles carrying specialist equipment, RAF mountain rescue team pick-up trucks and other vans transporting American personnel drove through Salthouse and Cley yesterday.

Mr Scully added: “We have now started the process of recovering the evidence. We hope the community will be tolerant of the disruption caused.”

A white tent has been put up on the crash site, which could take several weeks to investigate, and diggers were seen moving around the beach area.

It is not known when the second RAF Lakenheath helicopter, which was also on an exercise at the time of the crash on Tuesday, will be removed from the beach area.

Crew members from the aircraft attempted to rescue the four air crew who died, in the aftermath of the accident.

Bullets from the destroyed Pave Hawk helicopter remain scattered in the marshland and shingle among the debris but do not pose a threat.

The weather which had “deteriorated” had hampered the rescue effort but had not made it impossible, according to Mr Scully.

It is understood the A149 between the Dun Cow pub in Salthouse and Old Woman’s Lane in Cley will remain shut until next week.

Police said no evidence had been found to suggest the crash was a criminal matter and would hand over their work to date to the crash investigators.

The USAF, supported by the Ministry of Defence, will then lead the continuing investigation into the circumstances of the crash.

Assistant chief constable Nick Dean, who has led the police response to the crash, said: “As has been the case throughout this investigation, our thoughts remain with the families and friends of the military personnel who lost their lives in this tragic incident.

“Even though our colleagues from the USAF, supported by the MoD, will now lead the ongoing enquiries, we will continue to support their work, engaging with local communities and providing reassurance and assistance where required.”

Norfolk coroner Jacqueline Lake said she had completed her preliminary enquiries

She said: “I wish to offer my sympathy to the families, friends and colleagues of the four service personnel who died.”